Altered trans-regulatory control of gene expression in multiple anthocyanin genes contributes to adaptive flower color evolution in Mimulus aurantiacus.
Mol Biol Evol
; 26(2): 433-44, 2009 Feb.
Article
en En
| MEDLINE
| ID: mdl-19029190
A fundamental goal in evolutionary biology is to identify the molecular changes responsible for adaptive evolution. In this study, we describe a genetic analysis to determine whether the molecular changes contributing to adaptive flower color divergence in Mimulus aurantiacus affect gene expression or enzymatic activity. High performance liquid chromatography analysis confirms that flower color differences are caused by the presence versus absence of anthocyanin pigments. Cosegregation analysis and in vitro enzymatic assays rule out mutations that affect enzymatic function in the anthocyanin pathway genes. By contrast, cosegregation of gene expression with flower color suggests that tissue-specific differences in pigment production are caused by the coordinated regulatory control of three anthocyanin pathway genes. We provide evidence indicating that these expression differences are caused by a locus that acts in trans- and explains 45% of the phenotypic variance in flower color. A second locus with sequence similarity to the R2R3 MYB family of transcription factors explains 9% of the variation but does so in a complex fashion. These results demonstrate one of only two examples where we have clear evidence of both the adaptive nature of a flower color transition and evidence for its genetic basis. In both cases, mutations appear to affect expression of the anthocyanin structural genes. Future studies will allow us to determine whether these differences represent a real bias in favor of mutations that affect gene expression.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Regulación de la Expresión Génica de las Plantas
/
Mimulus
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Biol Evol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos